Create a custom button for a tooltip

[OccultScientist]

Hi,

I'm trying to create a custom button for the editor that shows a modal with a text input when clicked.
Once saved, it will insert a local image (a small question mark) that, when hovered over, will show a tooltip using Laravel Popper (https://andcarpi.github.io/laravel-popper/) that contains the entered test.

I'm really struggling, and any help would be most welcome.

Thanks!

[OccultScientist]

Or even a pointer to how to write a custom button would be good :)